Protective Effect of Amifostine against Etoposide-Induced Genotoxicity Evaluated By the Comet Assays

Abstract

Etoposide is one of the most effective chemotherapeutic agents used for the treatment of number of neoplasia. However, as a topoisomerase inhibitor, during clinical use several side effects may occur. In addition in several in vivo and in vitro studies etoposide has shown a range of genotoxic effects including mutation induction and inhibition of DNA synthesis. Amifostine, an organic thiophosphate prodrug, has been shown to exert important cyto-protective effects in many tissues. The aim of this study was to explore whether amifostine protects against etoposide-induced genotoxicity in HepG2 cell line. HepG2 cells (25×10 4 cells/well) were cultured in 24-well plates: a control group and three ‘amifostine etoposide groups (pre and cotreatment conditions). Our results show that etoposide induced a noticeable genotoxic effect in HepG2 cells. Amifostine reduced the effects of etoposide significantly in both type of experiment conditions, through reduced the level of DNA damage measured via comet andmicronucleus assay. Furthermore, amifostine decreased the intracellular ROS generation induced by etoposide. It increased also the intracellular GSH levels in HepG2 cells. Altogether, our results suggest a protective action of amifostine against etoposide cytotoxicity and genotoxicity via various pathways. The most protective effect was observed with amifostine when it was administrated 24 h before etoposide treatment.